Abstract

The compression of laser pulses at 527 nm, 250 fs long, down to 30 fs is reported. The laser pulses, originated from a frequency-doubled, mode-locked Nd:glass laser, were compressed by a 0.7-m-long, 150-μm-bore-diameter argon filled hollow fiber and a pair of SF10 prisms with a final energy of 160 μJ. These are the shortest, high energy pulses ever produced by direct pulse compression at the central wavelength of 527 nm. The spectral broadening of the pulses propagating inside the hollow fiber was experimentally examined for various filling-gas pressures and input pulse energies. The physical limitations of the hollow-fiber
pulse compression technique applied in the visible range are also studied. An application to laser ablation of Ni target is performed. Metal nanoparticles are obtained both with the 250-fs and with the 30-fs pulse.